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Tesla Model S HV battery heater replacement: fixed the same day

A Model S came in with a high-voltage battery heater fault. It was still driveable, but faults like this escalate quickly. With genuine Tesla heaters in stock, we replaced it and had the car back on the road the same day.

personBy Gabor, MegaEV calendar_today 2 min read

A red Tesla Model S in the MegaEV workshop with its bonnet open and the battery heater units on the floor in front of it

This Model S came in with a high-voltage battery heater fault.

Why it could not wait

The car was still driveable, and there was no isolation fault yet. But faults like this can, and will, escalate quickly, until the car cannot operate at all. So the owner needed a quick repair.

The battery heater keeps the high-voltage battery at a healthy temperature in cold weather. That matters for driving, for regenerative braking and for charging, so a failing heater is not something to leave until it stops the car.

Parts in stock, repair the same day

We keep genuine Tesla HV battery heaters and PTC heaters in stock. That meant we could fit the car in between other jobs at short notice, and complete the repair without waiting for parts.

The front end of the red Tesla Model S stripped down to reach the battery heater assembly
The front end stripped to reach the heater assembly.

The work:

  • stripped the front end to reach the heater assembly
  • replaced the faulty heater unit
  • tested the system and purged the coolant system with Tesla diagnostics, to confirm everything was working correctly
Two battery heater units with orange high-voltage cables on the workshop floor, one still in its box
The heater units: the faulty one out, the new genuine Tesla unit ready to fit.
The new battery heater assembly in place in the Tesla Model S, with its orange high-voltage connections
The new heater assembly in place.

A health check as standard

As with every car that comes in, we also carried out a general health check. The owner left with the heater fault fixed and the whole car checked over.

Back on the road the same day.

Got a battery heater or thermal warning?

Battery heater and thermal faults are worth looking at early, before they leave you stranded. Read more about why thermal management matters in our Model X thermal system repair entry, or see our air conditioning and thermal management service.

If your Tesla is showing a battery heater, thermal or high-voltage warning, send us a message and tell us what the screen says.

Related service

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